[Autoimmune pancreatitis]

Autoimmune pancreatitis is a relatively rare form of chronic pancreatitis which is characterized by a lymphoplasmatic infiltrate with a storiform fibrosis and often goes along with painless jaundice and discrete discomfort of the upper abdomen. Clinically we distinguish between two subtypes, which differ in terms of their histology, clinical picture and prognosis. Type 1 autoimmune pancreatitis is the pancreatic manifestation of the IgG4-associated syndrome which also involves other organs. About one third of the patients can only be diagnosed after either histological prove or a successful steroid trail. Type 2 is IgG4-negative with the histological picture of an idiopathic duct centric pancreatitis and is to higher degree associated with inflammatory bowel disease. A definitive diagnosis can only be made using biopsy. Usually both forms show response to steroid treatment, but in type 1 up to 50 % of the patients might develop a relapse. The biggest challenge and most important differential diagnosis remains the discrimination of AIP from pancreatic cancer, because also AIP can cause mass of the pancreatic head, lymphadenopathy and ductal obstruction. This article summarizes recent advances on epidemiology, clinical presentation, diagnostic strategy, therapy and differential diagnosis in this relatively unknown disease.